nerve supply to the nose and sinuses

Last reviewed 01/2018

The nerve supply may be divided into special sense, sensory and autonomic nerve supply.

Special sense is mediated by the olfactory nerves, of which there are about twenty. Fibres pass from receptors in the olfactory epithelium in the upper part of the nasal septum and medial wall of the superior turbinate through the cribriform plate of the ethmoid bone to the olfactory bulb. Second order neurones run from the bulb in the olfactory tract, eventually to cortical centres in the dentate and semi-lunate gyri.

The sensory nerve supply is provided through the ophthalmic and maxillary branches of the trigeminal nerve.

The autonomic innervation provides secretomotor and vasomotor control.

The sympathetic fibres cause vasoconstriction and reduce secretion. They originate in the first five segments of the thoracic spinal cord and synapse in the superior cervical ganglion. Post-ganglionic fibres reach target sites by running with blood vessels.

The parasympathetic fibres cause vasodilatation and increase secretion. They originate in the lacrimal nucleus and leave the brain stem in the nervous intermedius - part of the facial nerve. They relay in the pterygopalatine ganglion and enter the nasal cavity.